From patchwork Fri Mar 1 13:28:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 10835331 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 576A81880 for ; Fri, 1 Mar 2019 13:28:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41BAD2EE31 for ; Fri, 1 Mar 2019 13:28:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 34F2C2F72C; Fri, 1 Mar 2019 13:28:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B9C172EE31 for ; Fri, 1 Mar 2019 13:28:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=I4wW+wFyYue+sIWF+ZaeO4vyJVLz4wrKR6lAX9ocv+A=; b=W95Cdgt+DIhW7DfVATB3kJ+UCG ay1lwZKQzQBjrEUKMcPew9ZXHTw2+ti/fKTgZIOAWFyfIOO/5bbi0LujjIOEFXJ34g1JsTaeOxUrV zQRFrumTLblpemuw9N3CchQIvIxWMPuJtRTfgnArcAcdwA9NsE/08mUws8qKspdwQx6RVYNp7kF5o aQsTm2kgBAw7Rx5gq5sxXoYpLGem1XQVLz/FWvEbOa89/q+qP/hWaddGi7PKwE0BWcoXNFyn/EJbv 3ltZLQ+aj6dHcB7XWnqsxxWWWtFl5gD2WOssrdxALovk/3B4KXMPZF/1KabkNP1eL8qMS+80QmdRX stb7im1Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gziD6-0005PC-L3; Fri, 01 Mar 2019 13:28:20 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gziD3-0005O0-8d for linux-arm-kernel@lists.infradead.org; Fri, 01 Mar 2019 13:28:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 54D6B165C; Fri, 1 Mar 2019 05:28:16 -0800 (PST) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 44FF13F5C1; Fri, 1 Mar 2019 05:28:15 -0800 (PST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 01/10] arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals Date: Fri, 1 Mar 2019 13:28:00 +0000 Message-Id: <20190301132809.24653-2-will.deacon@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190301132809.24653-1-will.deacon@arm.com> References: <20190301132809.24653-1-will.deacon@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190301_052817_308603_1D39F036 X-CRM114-Status: GOOD ( 13.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, catalin.marinas@arm.com, Will Deacon , stable@vger.kernel.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by taking a hardware watchpoint. Unfortunately, if a debug handler returns a non-zero value, then we will propagate the UNKNOWN FAR value to userspace via the si_addr field of the SIGTRAP siginfo_t. Instead, let's set si_addr to take on the PC of the faulting instruction, which we have available in the current pt_regs. Cc: Signed-off-by: Will Deacon Reviewed-by: Mark Rutland --- arch/arm64/mm/fault.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index efb7b2cbead5..ef46925096f0 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -824,11 +824,12 @@ void __init hook_debug_fault_code(int nr, debug_fault_info[nr].name = name; } -asmlinkage int __exception do_debug_exception(unsigned long addr, +asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr, struct pt_regs *regs) { const struct fault_info *inf = esr_to_debug_fault_info(esr); + unsigned long pc = instruction_pointer(regs); int rv; /* @@ -838,14 +839,14 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); - if (user_mode(regs) && !is_ttbr0_addr(instruction_pointer(regs))) + if (user_mode(regs) && !is_ttbr0_addr(pc)) arm64_apply_bp_hardening(); - if (!inf->fn(addr, esr, regs)) { + if (!inf->fn(addr_if_watchpoint, esr, regs)) { rv = 1; } else { arm64_notify_die(inf->name, regs, - inf->sig, inf->code, (void __user *)addr, esr); + inf->sig, inf->code, (void __user *)pc, esr); rv = 0; }